The patent is directed to shutters, and more particularly to a rolling protective shutter and build-out dowels for fastening the rolling protective shutter about an opening of a wall having an uneven surface.
Hurricane protection is desired more and more by business owners, home owners and municipalities, and the engineering and testing requirements for such protection are becoming increasingly stringent and rigorous. Many different solutions have been implemented in the attempt to protect structures from the varying forces and conditions associated with hurricanes. For example, openings for windows, doorways, porches and the like require protection from the forces created by the severe winds associated with the hurricanes that cause positive pressure pressing against the openings on the windward side of the structure, and negative pressure pulling outwardly from the opening on the leeward side of the structure.
One attempted solution for protecting openings is the installation of panels attached to the surrounding support structure of the building defining the opening such that the opening is essentially isolated from the surrounding environment. The panel configured to cover an opening defined by the surrounding structure, and having a window or door disposed therein. The panel has a plurality of openings around the perimeter of the panel configured to receive fasteners that will anchor the panel to the surrounding structure on the both sides and above and below the opening. The panels are fabricated from material that may withstand the conditions present during the hurricane, such as metal, plywood, fabric and the like.
As an alternative to such panels, rolling protective shutters have been implemented for protection openings during hurricanes for many years. FIG. 1 illustrates an example of a rolling protective shutter 30 configured to cover an opening 12 defined by a surrounding structure 14 and having a window 16 disposed therein. The rolling protective shutter 30 may be permanently attached to the structure 14 surrounding the opening 12, and include deployment mechanisms for quickly rolling and unrolling the shutter curtain. The shutter assembly 30 has a shutter housing which includes a top wall 32, a pair of side walls or end caps 34, and a front wall 36. A shutter support member 40 is mounted for rotation within the shutter housing. The support member 40 includes a generally cylindrical central shaft 42 and a plurality of mounting members 44 fixed to the shaft 42. The upper end of a rolling shutter 50 is coupled to the mounting members 44. The shutter 50 is composed of a plurality of individual, elongate slats 52 interconnected by hinges 54. The ends of the slats 52 are disposed within a pair of shutter tracks or side tracks 60.
The illustrated shutter assembly 30 has a gearbox 62 which interconnects the rotatable shaft 42 with a hand crank 64 via a conventional gear assembly (not shown). When mounted to protect a window or other opening, the shutter tracks 60 of the shutter assembly 30 are positioned on either side of the opening and attached to the walls with fasteners, and the shutter housing is positioned over the top of the opening. Alternatively, in some applications, the side tracks 60 and shutter housing are positioned within the opening. When the shutter 50 is not in use, it is rolled up on the shutter support member 40 via the hand crank 64 so that it is at least partially enclosed by the shutter housing. The hand crank 64 may be disposed on a rear portion of the shutter assembly 30 so that the shutter 50, when attached over a window for example, can be unrolled from inside the window. Alternatively, when the gearbox 62 is not provided, the support member 40 may include a torsion spring. The shutter 50 may be rolled and unrolled with the assistance of the tension in the spring by exerting a force on a bottommost slat 66 by grasping a handle 68 that extends longitudinally along the slat 66 and outwardly from the shutter 50. Other drive mechanism, such as straps, tubular operators and motors are well known in the art and are used to open and close rolling shutters.
To prevent the shutter curtain 50 from pulling out of the side tracks 60 and to increase the capacity of the shutter curtain 50 to withstand pressure loading during extreme conditions, end retention systems have been developed to hold the two ends of the slats 52 captive within the side tracks 60. FIGS. 2 and 3 illustrate an example of the shutter slats 52 and corresponding side track 60, respectively, configured to retain the ends of the slats 52 within the side track 60 when forces tend to cause the shutter curtain 50 to bow. Referring to FIG. 2, each slat 52 includes a double-wall slat portion 82, and is arc-shaped to facilitate rolling the shutter curtain onto the shutter support member 20. Each slat 52 further includes an elongated socket 84 integrally formed along the bottom edge 85 of the slat portion 82. A rod 86 is integrally formed along the top edge 87 of the slat portion 82. The rod 86 includes a groove or channel formed therein and running along the longitudinal length of the rod 86 to form an integral screw boss 88. The combined rod 86 and screw boss 88 approximate the shape of a second, smaller socket integrally formed on the edge 87 of the slat portion 82. The slats 52 are typically fabricated from extruded aluminum or polyvinyl chloride, but other materials and fabrication methods are known in the art.
The slats 52 are fabricated such that the inner diameter of the socket 84 is slightly larger than the outer diameter of the rod 86. The shutter curtain is assembled by sliding the rod 86 of one slat 52 into the socket 84 of the adjacent slat 52. The slats 52 are oriented with their concave surfaces on the same side of the shutter curtain so that the curtain rolls up properly onto the shutter support member 40. When the slats 52 are assembled, the rods 86 are pivotal within the sockets 84 to facilitate movement of the shutter curtain between the rolled and unrolled positions. Since the sockets 84 cover over half the diameter of the rods 86, the rods 86 are permanently retained within the sockets 84. The sockets 84 and rods 86 are configured to form a hinge that allows the connected slats 52 to rotate between a first position in which the sockets 84 and the rods 86 of the slats 52 are substantially linearly aligned, and a second position wherein the slat portions 82 combine to define an arc.
Once the shutter curtain is assembled, extension members 90 are attached to the screw bosses 88. The extension members 90 are adapted to keep the slats 52 vertically aligned and to captivate the shutter curtain within the side tracks 60 to prevent the shutter curtain from pulling out of the side tracks 60 during either an attempted break in or extreme wind conditions. Each of the extension members 90 has an inner flange 92 and an outer flange 94 separated by a neck 96 having a smaller diameter than the flanges 92, 94. Each extension member 90 further includes a threaded shank 98 that is dimensioned to correspond to the screw boss 88. The extension members 90 are attached to the shutter curtain by screwing the shanks 98 into the screw bosses 88 so that the extension members 90 are attached to both ends of a given screw boss 88.
The extension members 90 extend outwardly from the shutter curtain and the outer flanges 94 are captivated by the side tracks 60, as shown in FIG. 3, and prevent the shutter curtain from being pulled out of the shutter tracks 60. Each side track 60 has a pair of side walls 102, 104, and an end wall 106. The side track 60 further includes a pair of fins 112, 114 that extend inwardly from the side walls 102, 104, respectively, and define a gap 116 wide enough to receive the neck 96 of the extension member 90. The neck 96 of the extension member 90 extends through the gap 116 so that the outer flange 94 is disposed on the opposite side of the fins 112, 114 from the inner flange 92 and slat 52. The diameter of the outer flange 94 is larger than the gap 116 between the fins 112, 114 so that the outer flange 94 cannot be pulled through the gap 116. When the shutter curtain is subjected to a force perpendicular to its surface, the slats 52 bow and the ends of the slats 52 move toward the opening in the side tracks 60. As the slats 52 bow, the outer flanges 94 of the extension members 90 are engaged by the fins 112, 114 of the side track 60 to retain the ends of the slats 52 within the side track 60. Similarly, the slats 52 bow inwardly when sufficient positive pressure is applied to the shutter curtain.
Other examples of slats for rolling shutter curtains configured to receive retention mechanisms for retaining the ends of the shutter curtains within the side tracks can be found in U.S. Pat. No. 6,095,224, entitled “Shutter Tracks for Rolling Protective Shutters,” U.S. Pat. No. 6,095,225, entitled “Shutter Slat with Integrated Screw Boss,” and U.S. Patent Publication No. 2005/0205221 A1, entitled “Dual Boss Shutter Slat with Retention Plate,” the entire disclosures of which are incorporated herein by reference. In each case, retention members are connected to the ends of the slats of shutter curtains, and the side tracks are configured to engage the retention members and retain the ends of the slats within the side tracks.
The shutters may be attached to the exterior surfaces 14 of buildings substantially as described above where the exterior surface 14 is substantially flat and there is no outwardly extending framing around the opening, or other obstructions such as door handles, hinges and the like. On such surfaces, the panel or shutter may be mounted flush against the surface via the fasteners, and the surface need only be pierced by holes that are large enough to receive the fasteners. In many installations, however, the shutters must be installed on various types of exterior surfaces that are not substantially flat and do not allow the shutters to be mounted flush against the surface. Consequently, exterior material such as shingles, siding, stucco and dryvit, for example, result in uneven surfaces in general and at the openings around which the shutters are to be mounted. For example, FIG. 4 illustrates an opening 200 having a window 202 surrounded by an upstanding window frame 204 in a wall 206 having an exterior surface consisting of siding planks 208. Such walls 206 typically have a subsurface secured to the support structure or framing of the building and the external protective surface in the form of the siding 208 installed over the subsurface. The siding 208 protects the subsurface from the elements and is installed in a manner to keep wind, rain, snow and other types of weather away from the subsurface to preserve the integrity of the wall. Moreover, the adjoining surfaces of the siding 280 and the window frame 204 are sealed to further protect the subsurface in areas that may otherwise leak.
While the construction materials causing the uneven surfaces protect the subsurface, they do not provide an adequate surface and structure for mounting shutters 30 thereto. The materials typically do not have sufficient strength to support the shutters 30, even where the shutters 30 are mounted through the exterior layer and into the subsurface. Instead, a flat surface is necessary for mounting the shutters 30 to the wall. FIGS. 4-7 illustrate the current method for mounting the shutters 30 to walls 206 having uneven surfaces such as wood siding 208 wherein an additional support frame 210 is provided to secure the shutters 30 to the wall 206. Referring to FIG. 5, the shutters 30 are mounted to the subsurface 212 by removing a portion of the siding planks 208 forming the external protective surface. In the present example, portions of the pieces of siding 208 around the opening 200 and the frame 204 are cut away to expose the corresponding portion of the subsurface 212. With the external surface removed, the support frame 210 is used to mount the shutter 30 to the subsurface 212 as shown in FIG. 6, and provides clearance from the window frame 204 so the shutter 30 may be lowered over the opening 200. As best seen in FIG. 7, the support frame 210 is recessed in the cut away opening through the siding 208 and rests against the subsurface 212. The support frame 210 is secured to the subsurface 212 and/or the interior framing 214 surrounding the opening 200 by appropriate fasteners 216, and the shutter housing and side tracks 60 are secured to the support frame 210. Similar installations may also be required where the exterior surface of a wall is flat but the material from which the exterior surface is fabricated is brittle such that the shutter housing and side tracks 60 may cause the material to crack or crumble when the rolling protective shutter is mounted tightly against the surface.
As discussed above, the exterior surface protects the subsurface from the elements. Once the exterior surface is pierced and a portion removed to accommodate the frame, the protection provided by the exterior surface is compromised. The exposed portions of the subsurface are now vulnerable to the elements. Also, the edges of the siding planks are exposed to the wind which can potentially pull the siding away from the subsurface. Consequently, once the shutter and/or the frame are installed, careful attention is required to reestablish the protection for the subsurface and prevent the loss of integrity of the structure. Such attention can be time consuming, expensive, and can even damage the structure that the shutters are intended to protect if not performed properly. For these reasons, a need exists for an improved method for installing rolling shutters on uneven surfaces that does not compromise the integrity of the structure.